1454
J. Org. Chem., Vol. 37, No. 9, 1972
NOTES
For mechanistic considerations, since only one oxygen atom is incorporated, it is reasonable to assume that it is the oxygen atom at C-7 of 7 which is incorporated from bisulfite. Any mechanism proposed for this transformation must be consistent with the following observations: (a) thebaine is unaffected by a bisulfite solution in the absence of 0 2 ; (b) molecular oxygen must be present during the course of the reaction in order for the conversion to occur; and (c) the source of the oxygen atom which is incorporated into the product is bisulfite. These conditions have been incorporated in the mechanism proposed in Scheme I. The postulated first SCHEME I
g of a 2: 1 mixture of thebaine and 7 and the second extract produced 0.14 g of a 3:2 mixture of the thebaine and 7. The aqueous phase was adjusted to pH 8.0 with concentrated HCl and extracted with methylene chloride (four 75-ml portions). The extracts were combined and dried (NazSO4) and the solvent was removed in vacuo to yield 7, 5.10 g (64%) based on thebaine consumed, as a white solid after crystallization from benzene, mp 184-186’’ turning red-brown, identical with material prepared by the action of alkali on 14-bromo~odeinone.~~~ Isotopic Experiments. A. 1 8 0 Determinations.-Reactions were carried out for 1 hr in the presence of H2180, l 8 0 2 , or NaHS180a, and the purified product was examined for l80by nonoxidative pyrolysis as previously described .s The l80content of the carbon monoxide produced was determined by mass spectrometry. Pyrolysis of an equal amount of unlabeled product provided a natural abundance background determination. The I8O content of the H P 0 and 0 2 used are 2.0 and 1.6%, respectively. All isotope assays were performed using a Consolidated Electrodynamics Corp. Model 130 mass spectrometer. B. Apparatus.-The oxidations were conducted in an apparatus’ which is commonly used for hydrogenation at atmospheric pressure, fitted for the introduction of oxygen instead of hydrogen. All experiments using isotopically enriched materials were conducted with this apparatus.
Registry No.-7, 27669-33-6. 1
2
J.
(7) K. B. Wiberg, “Laboratory Teohnique in Organic Chemistry,” McGraw-Hill, New York, N. Y., 1960, p 228.
A Novel Intramolecular Rearrangement of a 1,4 Dipole KENNETH B. WAGENER, S. RICHARD TURNER, AND GEORQE B. BUTLER*
Hi0 4
3
Department of Chemistry, University of Florida, Gainesville, Florida 52601
J
Received September 14, 1971
OH 5
H i j
6
0 7
step is the 1,4 addition of two bisulfite radical ions to form the disulfonate 2. The radical ions in turn are proposed as formed by the action of oxygen on aqueous bisulfite, conditions which are well documented t o convert olefins to sulfonates an.d disulfonates6 via radical intermediates. Reaction then proceeds via displacement of the sulfonate at position 14 to form the p-sultone 3. The latter then collapses to 4 which is hydrolyzed to the a-hydroxy ketone 5. Tautomeric rearrangement to 6 is followed by p elimination to form the morphinandienone, 6-O-demethyl~alut~aridine(7). Clearly, alternatives exist for the route from p-sultone 3 to dienone 7 involving essentially the same principles. Experimental Section
6-0-Demethylsalutaridine (7).-A solution of 9 g of thebaine (1) in 250 ml of 1 N sodium bisulfite was shaken for 3 hr under an atmosphere of oxygen. The solution was then brought to p H 11 with 30% aqueous sodium hydroxide and extracted with two 75-ml portions of benzene-hexane, 1:1. After drying (Nasso4) and removal of the solvent, the first extract produced 0.67 (6) E. E. Gilbert, “Sulfonation and Related Reactions,” Interscience, New York, N. Y.,1965, p 150.
While cycloaddition reactions of 1,4 dipoles are well documented,l J intramolecular rearrangements of these dipoles have rarely been observed. We wish t o report experimental evidence for a unique 1,4-dipolar intramolecular rearrangement resulting from the reaction of 4-phenyl-l,2,4-triazoline-3,5-dioneS(1) with vinyl esters. Equimolar quantities of 1 and vinyl acetate (2) react in methylene chloride at 60” yielding l-formyl-2acetyl-4-phenyl-1,2,4-triazoline-3,5-dione(3) exclusively. Isopropenyl acetate (4) reacts in a similar manner to give l-acetylmethyl-2-acetyl-4-phenyl-1,2,4triaxoline-3,bdione ( 5 ) . A plausible mechanism for these reactions would involve the unusually stable 1,4 dipole4 ( 6 ) as the reactive intermediate, formed via initial reaction of the electronpoor nitrogen double bond with the electron-rich double bond of the vinyl ester. The 1,4 dipole, once formed, could undergo an intramolecular nucleyphilic attack by nitrogen on the carbonyl carbon displacing the ester oxygen (path a, Scheme I). Intramolecular nucloophilic attack by nitrogen is sterically hindered by large Rz groups, decreasing the relative yield of the product (1) R. Huisgen, Z.Chem., 8, 290 (1968). (2) E. K. Von Guatorf, D. V. White, B. Kim, K. Hess, and J. Leitich, J . Org. Chern., 86, 1155 (1970). (3) J. C. Stickler and W. H. Pirkle, i b i d . , 31, 3444 (1966). (4) 1,4 dipoles of a similar nature have previously been reported.6 (5) (a) Ref 2; (b) S. R . Turner, L. J. Guilbault, and G . B. Butler, J . Org. Chem., 86, 2838 (1971).
J. Org. Chem., V d . $7, No. 9, 197%
NOTES
1455
SCHEME Io
1 f
R,
I
N-N
O
